# Which Problems Are Solved
The execution handler projection handles all events to check if an
execution has to be provided to the worker to execute.
In this logic all events would be processed from the beginning which is
not necessary.
# How the Problems Are Solved
Add the current state to the execution handler projection, to avoid
processing all existing events.
# Additional Changes
Add custom configuration to the default, so that the transactions are
limited to some events.
# Additional Context
None
# Which Problems Are Solved
Currently ZITADEL supports RP-initiated logout for clients. Back-channel
logout ensures that user sessions are terminated across all connected
applications, even if the user closes their browser or loses
connectivity providing a more secure alternative for certain use cases.
# How the Problems Are Solved
If the feature is activated and the client used for the authentication
has a back_channel_logout_uri configured, a
`session_logout.back_channel` will be registered. Once a user terminates
their session, a (notification) handler will send a SET (form POST) to
the registered uri containing a logout_token (with the user's ID and
session ID).
- A new feature "back_channel_logout" is added on system and instance
level
- A `back_channel_logout_uri` can be managed on OIDC applications
- Added a `session_logout` aggregate to register and inform about sent
`back_channel` notifications
- Added a `SecurityEventToken` channel and `Form`message type in the
notification handlers
- Added `TriggeredAtOrigin` fields to `HumanSignedOut` and
`TerminateSession` events for notification handling
- Exported various functions and types in the `oidc` package to be able
to reuse for token signing in the back_channel notifier.
- To prevent that current existing session termination events will be
handled, a setup step is added to set the `current_states` for the
`projections.notifications_back_channel_logout` to the current position
- [x] requires https://github.com/zitadel/oidc/pull/671
# Additional Changes
- Updated all OTEL dependencies to v1.29.0, since OIDC already updated
some of them to that version.
- Single Session Termination feature is correctly checked (fixed feature
mapping)
# Additional Context
- closes https://github.com/zitadel/zitadel/issues/8467
- TODO:
- Documentation
- UI to be done: https://github.com/zitadel/zitadel/issues/8469
---------
Co-authored-by: Hidde Wieringa <hidde@hiddewieringa.nl>
